How to fix hiDPI issues when installing OpenSuse 42.2 Leap RC1in five steps

I have purchased ASUS Zenbook UX305. It is a good Ultrabook which good Linux support and hiDPI screen. Unfortunately the support of hiDPI screens in modern Linux distributions is still lacking. Thus I decided to write down this post to help others struggling with similar problems when installing OpenSuSE on laptops with high definition resolution screens. After applying the suggested fixes you will get a functional Linux Ultrabook.

Prerequisites

To install Leap on Zenbook UX305 you will need the following during the installation:

A USB stick 8Gb or larger (to store the installer). Download the installer from the OpenSuSE web site, and copy it into the stick using the dd command.

A USB mouse. Your touchpad will not work during the installation. The touch screen will work, but it will be quite painful to use.

Installation

Booting from the USB

The first challenge you will face is how to boot from the USB stick. To do so:

Plug in the USB stick into the USB port while Zenbook is powered off.

Hold down the Esc key, and power on Zenbook. Continue holding the Esc key until you see the Boot loader menu. Choose your USB stick from the menu.

If your USB drive is not seen in the boot menu, reboot Zenbook by pressing Ctrl+Alt+Del and hold Esc key again.

You will see the GRUB menu with a tiny font. Press the ‘t’ key on a keyboard and you’ll see the text prompt.

Using the cursor arrow keys, highlight the “Installation” entry and press ‘e’ key. This will open Grub line editor.

Using the cursor arrow keys, move the cursor to the end of the line starting with “linuxefi” and append the following: video=1280×960. The line should look like that:

linuxefi /boot/x86_64/loader/linux splash=silent video=1280×960

Press Ctrl+F10 to boot the installation.

Handling the small font

Unfortunately Leap currently does not let you choose the installation resolution, and the resolution you passed will only work for the console. Thus if you need to do any disk partitioning, you can switch to a console (Ctrl+Alt+F2), and do it there; use Alt+F7 to return back. A bug report has been filed.

Your touchpad also will not work during the installation, please use the external mouse. Another bug report has been filed.

The easiest way to install is to switch to console before going through the license agreement, perform any operations on your disk (adding/removing partitions), and then process with the installation in default settings, changing only the absolutely necessary things. Do not bother with network configuration or adding/removing applications – you can do it later, once your system is installed.

Configuration

Upon the first boot, you end up with the barely readable fonts everywhere – from GRUB to KDE, and with a non-working touchpad. This is normal, and we’re going to fix it now.

Fixing the KDE resolution

To fix the KDE resolution, launch the “Configure Desktop” KDE applet. Click on “Displays” icon, and scroll down the “Manage and configure monitors and displays”.

At the bottom there is a “Scale Display” button. Click on it, and move the slider to 2. Press Ok in this dialog, and press Apply in the Displays applet.

After this the screen is readable. You can also go and adjust the font size and icon sizes (don’t over-adjust).

Install the updated kernel by searching for “kernel-default”, going into the “Versions” tab and selecting the latest kernel (4.8.4.2 as of today).

Once kernel installs, reboot the machine.

Now your machine is not booting anymore, because the new kernel is not signed by the proper key, and it breaks Secure Boot, which has to be disabled. To do so:

Power off the machine, hold the F2 key and power it on. Keep holding the key until you enter BIOS setup.

In BIOS setup go to “Security” tab, and there enter “Key management”. Choose “Delete all Secure Boot variables”, and confirm the deletion. Press Esc; now it should say “Secure Boot Disabled” in the Security menu. Now you can go to Boot menu, go to Delete Boot Option, and remove the “opensuse-secureboot” option. Go to “Save and Exit” and save the settings.

Now your new kernel would boot, and your touchpad should be working.

Fixing the GRUB and console font size and Brightness keys

Open the Yast and go to Bootloader. In the Kernel Parameters add the following into the “Optional Kernel Command Line Parameters”:

acpi_osi= video=1280×800

Please note there is a space between the equal sign and “video”!

In the same tab choose the 1280×1024 resolution in the “Console resolution”.

Press Ok and reboot the machine. Now your GRUB screen should be shown in readable resolution, and brightness keys will work again.

Fixing the SDDM resolution

To fix the SDDM resolution, edit the file /etc/sddm.conf, and add the following line at the bottom:

ServerArguments=-dpi 166

Save the file, and after logout the screen should be readable.

Enlarging the system tray icon size

To enlarge the system tray icons, please edit the file ~/.config/plasma-org.kde.plasma.desktop-appletsrc

Find the line

iconSize=1

and replace it by

iconSize=2

This will make the system tray icons larger and a bit uglier, but at least they are recognizable now. If you don’t like new icons, feel free to revert this setting back to 1.

As you see, those are fairly easy steps for an experienced user. Hopefully the next release of Leap will include them already, and you would not have to perform them yourself!